Mixing paddle



y 1963 E. D. PHILLIPS 3,097,002

MIXING PADDLE Filed Sept. 9, 1960 INVENTOR lwmapmugw United States Patent 3,097,002 MIXING PADDLE Edwin D. Phillips, P.O. Box 188, Middlesex, NJ. Filed Sept. 9, 1960, Ser. No. 54,875 9 Claims. (Cl. 287-20) This invention relates to mixing devices and is directed particularly to improvements in mixing paddles.

Various branches of industry make use of material mixing machines which employ rotary mixer blades or paddles. Such mixing devices or machines are used particularly in the chemical, food and pharmaceutical industries and in this connection paddles or mixing blades of different sizes are frequently required which necessitates changing from one blade size to another in accordance with the quantity of the material to be mixed or stirred.

It is a particular object of the present invention, in view of the foregoing, to provide a new and novel type of mixing paddle wherein a novel means is provided for securing the blade to a shaft, which securing means permits the ready changing of the blade on the shaft, from one size to another, thereby making it possible to use the same shaft for a number of difierent types, shapes or sizes of blades.

A further object of the invention is to provide a novel mixing paddle wherein there is employed a shaft and a blade, with a means for effecting the rigid attachment of the blade to an end of the shaft without the employment of the usual locking or set screws but at the same time permitting the blade to be easily and quickly removed from the shaft for replacement by another blade.

The invention broadly contemplates the provision of a shaft or rod member which is designed to be secured at one end to a suitable source of rotary power whereby the shaft with an attached blade may be rotated. A blade member of suitable design is provided for attachment to the other end of the shaft and such attachment is effected by providing the said other end of the shaft with a slot of a size to receive the edge portion of a blade, the portions of the shaft on opposite sides of the slot straddling the blade body and bearing against opposite faces thereof.

The said edge of the blade body is provided with a notch into which a portion of the shaft at the inner end of the slot is fitted. inwardly of such notch the blade body has formed therethrough an opening which receives a locking band or ring which encircles the end of the shaft when the blade is fitted into the slot of the shaft. The locking band or ring is formed with an inside diameter slightly less than the overall diameter of the slotted end of the shaft which it encircles whereby when such end of the shaft is extended through the band the two portions of the shaft lying on opposite sides of the slot will be slightly compressed or forced together so as to effect a firm frictional gripping of the blade.

'Disengagement of the blade from the shaft end when desired is easily effected by tapping the edge of the blade and in blades of relatively small size, such as are used in chemical or pharmaceutical laboratories, the frictional engagement will maintain the necessary tight coupling between the blade and the shaft. Where conditions may be such as to require the use of large and heavy blades and supporting shafts, the locking connection provided by the shaft encircling band may be augmented by the employment of a set screw or the like.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming a part of this specification with the understanding, however, that the invention is not confined to a strict conformity with the showing of the drawings but may be changed or modified so long as such changes or modifications mark 3,097,002 Patented July 9, 1963 ice no material departure from the salient features of the invention as defined by the appended claims.

In the drawings:

FIG. 1 shows a mixing paddle constructed in accordance with the present invention.

FIG. 2 is a view in perspective and on an enlarged scale of the paddle or blade and the lower end of the supporting shaft showing the coupling between the two parts.

FIG. 3 is a view in perspective and on an enlarged scale showing the parts of the paddle in separated relationship with the locking band removed from the blade opening and below but aligned therewith and with the end of the shaft which it encircles.

:FIG. 4 is a sectional view taken substantially on the line 4-4 of FIG. 1.

FIG. 5 is a section view taken substantially on the line 5-5 of FIG. 4.

FIG. 6 is a view illustrating in side elevation another form or shape of blade which may be employed.

FIG. 7 is a view showing in side elevation still another shape of mixing blade.

FIG. 8 is a view in side elevation of a still further type or form of mixing blade.

FIG. 9 is a view in perspective illustrating a locking band having a set screw.

Referring now more particularly to the drawings, numeral 10 generally designates a mixing paddle constructed in accordance with the present invention.

The paddle 10 comprises a shaft 12, a blade, generally designated 14 and a locking band or ring generally designated 16.

The shaft 12 may be of any suitable length and formed of suitable material such as stainless steel or other material having the desired strength and rigidity. The top end 18 of the shaft may be of any form or shape to facilitate securing it in a chuck or other gripping means forming a part of machinery with which the paddle is to be connected for use and by means of which the paddle will be rotated on the longitudinal axis of the shaft 12.

No illustration is here made or believed necessary of the 'type of machine or apparatus with which the paddle may be used. Lt will be readily obvious that there are many different types of mixing machines in connection with which paddles of the type here shown may be employed. One type of such mixing machine or apparatus is disclosed in my copending application Serial No. 640, 424, filed February 15, 1957, now Patent No. 2,967,433.

The lower end 20 of the shaft 12 is provided with a slot 22, such slot here being shown as extending longitudinally of the shaft on the diametric-al center thereof and opening through the lower end of the: shaft.

The mixing blade 14 shown in FIGS. 1 to 5 is of rectangular form. This blade comprises a body or plate 24 formed of a suit-able material which may be either stainless steel or any other suitable metal or it may be formed of a suitable plastic such as, for example, Teflon.

The top edge 26 of the blade is provided midway of its ends or in the vertical center of the blade, with a notch 28 of a width slightly greater than the diameter of the end portion 20 of the shaft.

In vertical alignment with the notch 28 and spaced a suitable distance therefrom, the blade body 24 has formed therethrough the rectangular opening 30. The dimensions of this opening are such that the opening may receive the locking band 16.

The locking band 16 is here illustrated as comprising a short cylinder 32, the height or length of which approximates the height of the opening 30 while the outside diameter approximates the Width of the opening so that the band can be fitted snugly therein.

The inside diameter of the band is slightly less than the overall diameter of the lower end 20 of the shaft 12. In other words, the band provides a bore 34, the diameter of which is less than the diameter of the shaft, whereby when the slotted end of the shaft is inserted into the bore 34, the furcations 22a will be flexed slightly toward one another to effect the desired locking connection between the shaft and the blade in the manner hereinafter described.

As illustrated in FIG. 4, the slot 22 in the end of the shaft 12 is of a width slightly greater than the thickness of the blade or blade body 24. This figure also illustrates the manner in which the blade is gripped by the constricting action imposed by the bifurcated or slotted end of the shaft by the locking band 16.

It will be readily apparent from FIG. 3 that the assembling of the parts consists in inserting the portion of the top edge 26 of the blade body in which the slot 18 is formed, into the slot 22 so that the body of the shaft at the upper end of the slot will enter the notch 28, the bottom edge 28a of the notch seating against the bottom of the slot. Prior to this assembling of the blade and the shaft the locking band 16 is inserted in the blade opening 30 so that the slotted or bifurcated end of the shaft, when it is placed on the blade, will pass into or through the locking band to assume the position shown in FIG. 4. With further reference to this FIG. 4, it will be seen that when the ends of the furcations enter the locking band they will be forced together slightly and thus will firmly grip the blade body 24 so as to effect a tight frictional coupling between the blade and the shaft.

In chemical and other laboratories mixing operations are often carried out on a relatively small scale, that is, liquids or other materials in small quantity may be contained in a jar which may be of small diameter and under these conditions blades of a different type from that shown in FIGS. 1 to may be desirable for use as, for example, a blade of circular form or in the form of a disc such as that shown in FIG. 6 and generally designated 36 might be suitable for a particular operation or a blade of flat or semi-elliptical form or contour may be found suitable for use such, for example, as are illustrated in FIGS. 7 and 8 and generally respectively designated 38 and 45. Regardless of the size, configuration or thickness of the blade, such blade will be provided with a top edge notch similar to the notch 28 and with an opening below the notch and in line therewith, similar to the opening 30 so as to receive corresponding parts respectively of the lower end of a shaft and of a locking band.

In FIG. 6 the circular blade 36 has a notch 40 in the edge thereof and has an opening 42 in line with the notch. The blade in FIG. 7 designated 38, is provided with a similar notch 43 and an opening 44 [for the reception respectively of the shaft and locking band, while the blade 45, which is of semi-elliptical form, is provided with a top edge notch 46 and an opening 47 therebelow.

While the shaft 12 has been illustrated as being of circular cross section and the locking band has been shown as provided with a bore 34 of similar design, it will be understood that the invention is not limited to the use of shafts and locking bands of the designs shown, since a shaft of polygonal cross section may be employed together with a locking band having a bore or passage of corresponding configuration to receive the shaft. The shaft and blade may both be formed of stainless steel or other suitable metal and while such parts might be readily welded together to form a unitary structure, such structure would present corners and angles which would make cleaning of the paddle difiicult. With the present invention the parts can be readily separated for thorough cleaning and in addition only one shaft need be provided for use in association with a large number of blades of different sizes and shapes. Additionally, where the blades may be formed of Teflon or other plastic material, such blades can be readily secured to a metal shaft but it would not be possible, even if it were desirable, to weld the blade and shaft together, to weld the Teflon or other plastic blade to a metal shaft.

The present invention also has the desirable advantage that a kit of blades may be marketed with a single shaft adapted to have any one of the blades attached thereto, thus making it possible to provide for the industry a number of blades of different sizes and types, at a more economical figure than would be possible if every blade had to have a shaft of its own welded or otherwise permanently fixed thereto.

While the present invention is particularly well adapted for use in laboratories or other situations where machines are used for mixing materials in small quantities, large and heavy mixing paddles for heavy industrial use maybe constructed in accordance with the invention and in that case use may be made, if found desirable, of a set screw or like fastening means for fixing the locking band 16 to the bifurcated end of the shaft, thereby providing a doubly secure fastening between the parts. FIG. 9 illustrates such a locking band, which is here generally designated 16', the band body 32' having the opening or bore 34' and carrying the set screw S whereby the band may be locked to the bifurcated end of a shaft.

I claim:

1. A mixing paddle comprising a blade body having a top edge, a notch formed in said top edge, the body having an opening therethrough spaced from but aligned with the notch transversely of the blade, a shaft having a bifurcated end adapted to receive the notched edge of the blade and to position in the notch at the inner ends of the furcations, said furcations being of a length to extend across the opening of the blade when said notched edge is so engaged between the furcations, a locking band supported within the opening of the blade and having said furcations extended thereinto, 'and means for effecting a locking engagement of the band with the furcations.

2. A mixing paddle comprising a blade body having a top edge, a notch formed in said top edge, the body having an opening therethrough spaced from but aligned with the notch transversely of the blade, a shaft having a bifurcated end adapted to receive the notched edge of the blade and to position in the notch at the inner ends of the furcations, said furcations being of a length to extend across the opening of the blade when said notched edge is so engaged between the furcations, a locking band supported within the opening of the blade and having said furcations extended thereinto, and means for compressing the furcations against opposite sides of the blade to effect a frictional engagement between the furcations and the blade.

3. A mixing paddle comprising a blade body having a top edge, a notch formed in the said top edge, a rectangular opening in the blade in spaced relation with the notch and aligned therewith vertically of the blade, a shaft having one end bifurcated, a space between the furcations of said bifurcated end of the shaft being slightly greater than the thickness of the plate, said notched edge of the plate being insertable in the bifurcation and the shaft being of a width to fit in the notch at the inner end of the bifurcation, the furations being of a length to extend across said rectangular opening when the notched edge of the blade is fitted in the bifurcation, and a locking band adapted to be positioned in said rectangular opening and to receive the bifurcated end of the shaft, said band being of an interior size relative to the cross sectional dimension of the shaft to eifeot the forcing of said furcations together into frictional clamping engagement with the blade.

4. The invention according to claim 3, wherein said shaft in the bifurcated portion thereof is of circular cross section and wherein said locking band is in the form of a ring and is fitted tightly within said rectangular opening.

5. A mixing paddle comprising a blade body having a top edge and having two opposite parallel faces, the blade body having a rectangular opening through said faces, a shaft having a longitudinal slot in a portion of one end to receive the said top edge of the blade body, the slot forming two furcations which extend across said opposite faces of the blade body and across said rectangular opening, a locking member positioned within said rectangular opening and formed to receive the slotted end of the shaft, and means whereby said slotted end of the shaft is secured against disengagement from said locking member.

6. In a mixing paddle embodying a blade and a shaft, a means for operatively coupling the same together which comprises a slot in and extending longitudinally of the shaft from an opening through one end thereof, the slot being of a width to receive an edge of the blade whereby portions of the shaft extend over opposing side portions of the blade, an edge portion of the blade engaging the bottom of the slot, an annular band of a diameter to receive and snugly engage around a portion of the slotted end of the shaft and said blade having an opening therein of a size and configuration to snugly receive said band and the band encircling said slotted end of the shaft while positioned in said opening, and means securing the slotted end of the shaft in the band while the shaft is so encircled.

7. The invention according to claim 6 wherein the said edge portion of the blade engaging the bottom of the slot constitutes the bottom of a notch in the blade, opposite sides of which notch position along and engage opposite sides of the shaft beyond the bottom of the shaft slot.

8. The invention according to claim 6, wherein the inside diameter of the band is slightly less than the overall diameter of the slotted end portion of the shaft whereby the portions of the shaft at opposite sides of the slot are compressed against an interposed portion of the blade to frictionally lock the blade and shaft together.

9. The invention according to claim 6 wherein the last stated means comprises a set screw carried by the band for engagement with the shaft.

References Cited in the file of this patent UNITED STATES PATENTS 1,281,610 Lundahl Oct. 15, 1918 1,477,653 Barre Dec. 18, 1923 1,841,435 Gibson Ian. 19, 1932 2,143,401 Arvin Jan. 10, 1939 2,613,107 Hartnett Oct. 7, 1952 2,742,307 Elsner Apr. 17, 1956 FOREIGN PATENTS 704,842 Germany Apr. 8, 1941 164,086 Austria Sept. 26, 1949 

1. A MIXING PADDLE COMPRISING A BLADE BODY HAVING A TOP EDGE, A NOTCH FORMED IN SAID TOP EDGE, THE BODY HAVING AN OPENING THERETHROUGH SPACED FROM BUT ALIGNED WITH THE NOTCH TRANSVERSELY OF THE BLADE, A SHAFT HAVING A BIFURCATED END ADAPTED TO RECEIVE THE NOTCHED EDGE OF THE BLADE AND TO POSITION IN THE NOTCH AT THE INNER ENDS OF THE FURCATIONS, SAID FURCATIONS BEING OF A LENGTH TO EXTEND ACROSS THE OPENING OF THE BLADE WHEN SAID NOTCHED EDGE IS SO ENGAGED BETWEEN THE FURCATIONS, A LOCKING BAND SUPPORTED WITHIN THE OPENING OF THE BLADE AND HAVING SAID FURCATIONS EXTENDED THEREINTO, AND MEANS FOR EFFECTING A LOCKING ENGAGEMENT OF THE BAND WITH THE FURCATIONS. 